1. Field of the Invention
The invention relates to an apparatus for cooling a mold which is employed in injection molding machines or the like to form articles made of plastics.
2. Prior Art
A typical prior art apparatus for cooling a pair of mating molds is usually constructed in such a manner as shown in FIG. 6. Each mold in the pair comprises a coolant inlet and outlet disposed at its one side not in contact with the other mating mold. The apparatus comprises plugs P1 and P2 whose male-threaded legs "Q" are screwed into female-threaded apertures 2. A desirable length of hose "S" is connected at its ends to hose-retaining cylindrical portions "R" each having a stepped periphery which prevents the hose from being withdrawn. Disposed at another side opposite to the one side of the mold is the coolant inlet not shown in FIG. 6 (see FIG. 1). An appropriate cooling medium (hereinafter referred to as "coolant") which is in liquid state flows into mold through the coolant inlet in a direction shown at "X". The coolant subsequently penetrates the mold and then leaves it temporarily and through one of the plugs P1, before it enters the mold again through the hose "S" and the other plug P2. The returning coolant will penetrate again the mold, and flows out of it as shown by another arrow "Y". An indefinite length of hose is cut into the desirable length corresponding to a distance between the coolant inlet and outlet.
It is however disadvantageous that the plugs and the hose attached thereto in the prior art cooling apparatus do protrude sideways and outwardly a so great distance that a large space is required not only to mount the mold on a molding machine but also to house it in a workshop or toolshed. Further, such a projecting hose is likely to be damaged by collision with other objects, and is unsightly in its appearance. The hose is generally made of a rubber which will deteriorate in a short time due to a high temperature of the mold. Thus, the hose is not durable to a sufficient degree, and in the event that a hose which has a hole in its wall were use, it would disturb a molding process such as injection molding process to thereby cause a poor quality of molded products.